Question

Suppose I have an ArrayList of String and an ArrayList of int.

My ArrayList of Strings contains:

index : value
-----------------
0     : "Paul"
1     : "Peter"
2     : "Maria"

My ArrayList of Integers contians:

index : value
-----------------
0     : 2
1     : 0
2     : 1

Suppose I sort my int array using

Collections.sort(myArrayOfint);

The result should be 0 at index 0, 1 at index 1, and 2 at at index 2 right?

What I want to do is sort my String array taking in consideration my int Array’s new order, so for example “Paul” would go to index 1, “Peter” to index 2, and “Maria” to index 0. The order would be swapped same as my int array.

How can I do this, is it possible?

Answer 1

You can create class with the properties and use different Comparators that compares based on different properties:

public class Person {
    private String name;
    private Integer id;

    //getter/setter
}

List<Person> people = new ArrayList<Person>();

Collections.sort(people, new Comparator<Person>() {
    @Override
    public int compare(Person p1, Person p2) {
        return p1.getName().compareTo(p2.getName());
    }
});


Collections.sort(people, new Comparator<Person>() {
    @Override
    public int compare(Person p1, Person p2) {
        return p1.getId().compareTo(p2.getId());
    }
});